Bright blue flashes with a humming noise near lake Minnetonka

Last night (Feb. 28th) my wife and I were awoken by an extremely bright flash of blue light from our window. Once we were up I looked out the window, and again this extremely bright flash occurred. I likened it to lighting but it was blue, lasted about 10 seconds and there was no boom, but rather a dull hummm that lasted about 10 seconds. Very Very unusual!!

Anyone else see this??